Swivel knife



Aug. 27, 1957 J. L. BELANGER 2,803,877

SWIVEL KNIFE Filed June 1, 1954 FMMM fi trate This invention relates to cutting implements, and more particularly to swivel knives.

The cutting instrument here disclosed is intended for use in the graphic arts, for example, for manually cuting around designs or pictorial illustrations. For this purpose the knife customarily comprises a handle with which one or more blades may be used. In some knives the blades are rigidly secured in position. In others the blade comprises a cutting portion and a cylindrical shank, usually disposed at an angle to the cutting portion. This shank may be freely rotatably received in the holder, so that it tends to automatically swivel with a kind of caster action as the holder is moved.

One primary object of, the present invention is to provide a knife of the class described which may be readily converted from the free swivel type to the rigid type, or vice versa, at the option of the user. A further object is to releasably hold the blade in the holder so that the blade being used may be changed. in accordance with a further feature of the invention the handle portion of the holder is hollow, and closed at the top by means of a removable cap, so that the hollow handle may be used for storage of blades. A still further object of the invention is to localize the lock means for the blade at the lower end of the holder, thus leaving the main body or handle portion of the holder free for storage of blades.

To accomplish the foregoing general objects, and other more specific objects which will hereinafter appear, my invention resides in the swivel knife elements, and their relation one to another, as are hereinafter more particularly described in the following specification. The specification is accompanied by a drawing, in which:

Fig. 1 is a perspective view showing an assembled swivel knife embodying features of my invention;

Fig. 2 is an exploded view drawn in section and to larger scale;

Fig. 3 is a fragmentary section showing the parts of the holder assembled, but with the blade not yet inserted in the holder;

4 Fig. 4 is a view generally similar to Fig. 3, but showing the blade in the holder;

Fig. 5 is a transverse section taken approximately in the plane of the line 5-5 of Fig. 4, with the parts in position for free swivel action by the blade;

Fig. 6 is a section similar to Fig. 5 but showing the relation of the parts when the blade is frictionally gripped against rotation;

Fig. 7 is a localized elevation looking in the direction of the arrows 7--7 of Fig. 2; and

Fig. 8 is a perspective view showing one form of blade which may be used.

Referring to the drawing, and more particularly to Fig. 1, the knife comprises a holder H and a blade B. In Fig. 3 it will be seen that the blade includes a cutting portion 12 and a cylindrical shank id. The upper end of the shank is preferably tapered at 116. Spaced somewhat from the upper end the shank is reduced in diameter or necked as shown id. in most cases it is preferred atent 2,803,877 Patented Aug. 27, 1957 to dispose the cutting portion 12 and the shank 14 at an angle to one another.

Referring to Figs. 3 and 4, the lower end of the holder H has a socket hole 20 which receives the shank 14 of the blade. There is also a retainer means 22 to hold the blade while affording rotation thereof. An optionally useable locking means, generally designated L, locks the blade against rotation relative to the holder H when desired. This locking means is preferably knurled or roughened, as shown at 24, and preferably acts as a continuation or part of the surface of the holder, but the locking means is rotatable relative to the holder in order to change from locked to unlocked condition, or vice versa.

Considering the arrangement in greater detail, and referring to Fig. 2 of the drawing, the holder H comprises a handle portion 26 with a cylindrical stud 28 projecting from the lower end thereof. The socket hole 20 extends in axial direction through the stud 23, but is radially offset slightly from the axis of the stud, as will be seen from comparison of the hole it? with the center line (it) of the handle. The holder further comprises a hollow cap 32 dimensioned to be rotatably received over thestud 28. The lower end of the cap has a hole 34 which is dimensioned and offset from the center line 30 to register with the socket hole 24 in the stud. Thus when the parts are assembled as shown in Fig. 3, the holes 2% and 34 may be in perfect alignment, at which time the blade B is freely rotatable, as is evidenced in Fig. 4 by the clearance there shown around the shank 14. This clearance has been exaggerated in the drawing for clarity.

The holder is provided with means to retain the cap on the stud, and in the present case there is an annular retainer groove 36 (Fig. 2) around the inside wall of the cap 32. There is also a V-shaped retainer spring 38 received in a mating opening or slot 4t) passing through the wall of the stud 23. The inner arm of spring 38 carries the detent 22 which cooperates with the necked part 13 of the blade. The outer arm of the spring has a detent 42 which cooperates with the annular retainer groove 36. It will be evident from inspection of Fig. 2 that the cap may be pushed up over the stud, with the parts then assuming the relation shown in Fig. 3, in which the cap, handle and spring are held assembled. The blade is readily inserted, as shown by the change from Fig. 3 to Fig. 4. To remove the blade it is merely necessary to pull the same out.

Referring now to Figs. 5 and 6, it will be seen that by rotating the cap 32 relative to the stud 28, the hole 34 is displaced relative to the socket hole 20, and the shank 14 of the blade is frictionally gripped against rotation. Thus the cap acts as the locking means L. The eccentricity of the holes is such that the cap may be turned only a fraction of a revolution. The relative eccentricity of the holes would be a maximum if the cap were turned but the relation of the eccentricity to the clearance is preferably made such that the grip of the parts on the shank prevents the cap from being turned as much as 180. In other words, the possibility of going past dead center is preferably avoided. Because of the gradual displacement afiorded by the slight eccentricity of the parts, there is a wedging or jamming action which effectively grips the shank, and which at the same time holds the cap in its locking position.

To restore the free swivel action of the blade the cap is turned back to initial position. This position may be indicated by appropriate marks on the cap and handle, asv

shown at 44 in Fig. 1. Instead of indicator marks, or more preferably in addition to indicator marks, I provide detent means to help locate the free swivel position, and to help retain the cap in that position.

Reverting to Fig. 2, the groove 36 is deepened at one point to provide, a detent recess 46. This cooperates with thedetent 42 previously referred to. The dimension and arrangement of the parts is such that the cap may be turned when desired, and in such case is held against removal by the engagement of the detent 42 in the groove 36. However, when the cap is turned back to release position the detent 42 springs outward somewhat further into the detent recess 46, thus permitting the operator to sense through his fingers the free-swivel position in which the socket holes 34 and are in registration.

The handle 26 is preferably hollow as shown in Fig. 2, and the open upper end of the handle may be closed by i a suitable top 50. This is held by releasable means, here illustrated by a threaded engagement at 52. The hollow space 54 in handle 26 preferably is large enough to readily receive a number of blades.

In operation the user simply selects a desired blade and inserts it in the holder. The knife is then used as a swivel knife, but on reaching a part of the work where it is preferred to fixedly control the blade through the holder, the operator simply turns the knurled locking portion L relative to the handle portion H, thus frictionally gripping the blade against rotation. 'On completing that part of the work which requires a fixed blade, and again desiring a swivel blade, the operator simply turns the locking portion L relative to the handle H back to initial position.

It is believed that the construction and method of use of my improved swivel knife, as well as the advantages thereof, will be apparent from the foregoing detailed description. It will also be apparent that while I have shown and described the invention in a preferred form, changes may be made in the structure shown without departing from the scope of the invention, as sought to be defined in the following claims.

I claim:

1. A swivel knife comprising a holder having a handle portion, a cylindrical stud projecting from the lower end of said handle portion, a cylindrical socket extending in axial direction in said stud but offset slightly from the axis of the stud, and a cap rotatably received over said stud, the lower end of said cap having a hole dimensioned and offset to register with the cylindrical socket in the stud, a blade including a cutting portion and a cylindrical shank dimensioned to be rotatably received in said socket and hole, said blade being freely rotatable when the hole is in registry with the socket, said cap being rotatable when desired to move the hole out of registry with the socket in order to frictionally grip the blade against rotation.

2. A swivel knife comprising a holder having a handle portion, a cylindrical stud projecting from the lower end of said handle portion, a cylindrical socket extending in axial direction in said stud but offset slightly from the axis of the stud, and a cap rotatably received over said stud, the lower end of said cap having a hole dimensioned and offset to register with the cylindrical socket in the stud, a blade including a cutting portion and a cylindrical shank dimensioned to be rotatably received in said socket and hole, said blade being freely rotatable when the hole is in registry with the socket, said shank being necked, and said stud being provided with retainer means which cooperates with the necked part of the shank to retain the blade axially in the holder while affording free rotation thereof, means to hold the cap against axial movement on the stud while affording rotation of the cap, said cap being rotatable when desired to move the hole out of registry with the socket in order to frictionally grip the blade against rotation.

3. A swivelknife. comprising a holder having a handle portion, a cylindrical stud projecting from the lower end of said handle portion, a cylindricalsocket extending in axial direction in said stud but offset slightly fromthe axis of the stud, and a cap rotatably received over said stud, the lower end of said cap having a hole dimensioned and offset to register with the cylindrical socket and in the stud, a blade including a cutting portion and. a cylindrical shank dimensioned to be rotatably received in said socket and hole, said blade being freely rotatable when the hole is in registry with the socket, said shank being necked, and said stud being provided with retainer means which cooperates with the necked part of the shank to retain the blade axially in the holder while affording free rotation thereof, means to hold the cap against axial movement on the stud while affording rotation of the cap, detent means to hold the cap against rotation on the stud with the cap in proper orientation for free swiveling of the blade, but said cap being rotatable when desired to move the hole out of registry with the socket in order to frictionally grip the blade against rotation.

4. A swivel knife comprising a holder having a handle portion, a cylindrical stud projecting from the lower end of said handle portion, a cylindrical socket extending in axial direction in said stud but offset slightly from the axis of the stud, and a cylindrical cap rotatably received over said stud, the lower end of said cap having a hole dimensioned and offset to register with the cylindrical socket in the stud, a blade including a cutting portion and a cylindrical shank dimensioned to be rotatably received in said socket and hole, said blade being freely rotatable when the hole is in registry with the socket, said shank being necked, and said stud being provided with a retainer spring the inner end of which cooperates with the necked part of the shank to releasably retain the blade axially in the holder while affording free rotation thereof, the inner wall of said cap having an annular retainer groove cooperating with means to hold the cap against axial movement on the stud, said cap being rotatable to move the hole out of registry with the socket in order to frictionally grip the blade against rotation.

5. A swivel knife comprising a holder having a handle portion, a cylindrical stud projecting from the lower end of said handle portion, a cylindrical socket extending in axial direction in said stud but offset slightly from the axis of the stud, and a cylindrical cap rotatably received over said stud, the exterior of said cap being knurled or roughened and forming a continuation of the handle portion of the holder, the lower end of said cap having a hole dimensioned and offset to register with the cylindrical socket in the stud, a blade including a cutting portion and a cylindrical shank dimensioned to be rotatably received in said socket and hole, said blade being freely rotatable when the hole is in registry with the socket, said shank being necked, and said stud being provided with a'retainer spring the inner end of which cooperates with the necked part of the shank to releasably retain the blade axially in the holder while affording free rotation thereof, the inner wall'of said cap having an annular retainer groove cooperating with means to hold the cap against axial movement on the stud, said cap also having a detent recess cooperating with resilient means to hold the cap against rotation on the stud with the cap in proper orientation for free swiveling of the blade,

but said cap being rotatable when desired to move the hole out of registry with the socket in order to frictionally grip the blade against rotation.

6. A swivel knife comprising a holder having a handle portion, a cylindrical stud projecting from the lower end of said handle portion, a cylindrical socket extending in axial direction in said stud'but offset slightly from the axis of the stud, and a cylindrical cap rotatably received over said stud, the exterior of said cap being knurled or roughened and forming a continuation of the handle portion of the holder, the lower end of said cap having a hole dimensioned and offset to register with the cylindrical socket in the stud, a blade including a cutting portion and a cylindrical shank dimensioned to be rotatably received in said socket and hole, said shank being necked, and said stud being provided with a V-shaped retainer spring the inner arm of which cooperates with the necked part of the shank to retain the blade in the holder while affording free rotation thereof, the inner wall of said cap having an annular retainer groove cooperating with the outer arm of said V-shaped retainer spring to hold the cap on the stud, said cap being rotatable when desired to move the hole out of registry with the socket in order to frictionally grip the blade against rotation.

7. A swivel knife comprising a holder having a handle portion, a cylindrical stud projecting from the lower end of said handle portion, a cylindrical socket extending in axial direction in said stud but ofiset slightly from the axis of the stud, and a cylindrical cap rotatably received over said stud, the lower end of said cap having a hole dimensioned and offset to register with the cylindrical socket in the stud, a blade including a cutting portion and a cylindrical shank dimensioned to be rotatably received in said socket and hole, said shank being necked, and said stud being provided with a V-shaped retainer spring the inner arm of which cooperates with the necked part of the shank to retain the blade in the holder while affording free rotation thereof, the inner wall of said cap having an annular retainer groove cooperating with the outer arm of said V-shaped retainer spring to hold the cap on the stud, said cap also having a detent recess cooperating with said retainer spring to hold the cap in proper orientation for free swiveling of the blade, but said cap when turned with sufficient force to override the yieldable detent action of said retainer spring being rotatable when desired to move the hole out of registry with the socket in order to frictionally grip the blade against rotation.

8. A swivel knife comprising a holder having handle portion, a cylindrical stud projecting from the lower end of said handle portion, a socket hole extending in axial direction in said stud but offset slightly from the axis of the stud, and a cylindrical cap rotatably received over said stud, the exterior of said cap being knurled or roughened and forming a continuation of the handle portion of the holder, the lower end of said cap having a hole dimensioned and offset to register With the socket hole in the stud, a blade including a cutting portion and a cylindrical shank dimensioned to be rotatably received in said socket hole, said shank being necked, and said stud being provided with a V-shaped retainer spring the inner arm of which cooperates with the necked part of the shank to retain the blade in the holder while affording free rotation thereof, the inner wall of said cap having an annular retainer groove cooperating with the outer arm of said V-shaped retainer spring to hold the cap on the stud, said cap also having a detent recess cooperating with said retainer spring to hold the cap in proper orientation for free swiveling of the blade, but said cap when turned with sufficient force to override the yieldable detent action of said retainer spring being rotatable to move the hole out of registry with the socket in order to frictionally grip the blade against rotation, the detent action on the blade when in free swivel position being such that the blade may be pulled out of the socket for replacement.

9. A swivel knife comprising a holder having a handle portion, a cylindrical stud projecting from the lower end of said handle portion, a cylindrical socket extending in axial direction in said stud but offset slightly from the axis of the stud, and a cap rotatably received over said stud, the lower end of said cap having a hole dimensioned and offset to register with the cylindrical socket in the stud, a blade including a cutting portion and a cylindrical shank dimensioned to be rotatably received in said socket and hole, said blade being freely rotatable when the hole is in registry with the socket, said shank being necked, and said stud being provided with a resilient retainer means which cooperates with the necked part of the shank to retain the blade axially in the holder while affording free rotation thereof, means to hold the cap against axial movement on the stud while affording rotation of the cap, said cap being rotatable when desired to move the hole out of registry with the socket in order to frictionally grip the blade against rotation, the detent action of the resilient retainer means on the shank when in free swivel position being such that the blade may be pulled out of the socket for replacement.

References Cited in the file of this patent UNITED STATES PATENTS 835,160 Lutz et a1. Nov. 6, 1906 861,423 Ayers July 30, 1907 1,775,813 Colby Sept. 16, 1930 2,659,143 Baker Nov. 17, 1953 FOREIGN PATENTS 465,258 Great Britain May 4, 1937 

